For additional information on VISTA please refer to the official web site.

GENERAL INFORMATION ABOUT VISTA DATA PRODUCTS

Rice image compression

CASU is using the Rice lossless compression to store both the raw and reduced data. Rice compression is supported by CFITSIO and by DS9 (starting from version 5). You can use funpack to uncompress the images.

Astrometry

CASU is using the Zenithal Polynomial projection (ZPN) to encode the astrometric calibration in the FITS headers. Although ZPN is part of the FITS standard for WCS encoding, it is not supported by old IRAF versions. ZPN is instead correctly understood by other software packages like DS9 and Gaia. For more information on how to fix this problem, see the IRAF ZPN Patch document. If you use Terapix software (e.g., SExtractor or Swarp), check out the Terapix Software ZPN howto document to learn about ZPN-related issues.